The girls were born in Kiowa County Kansas to Elmer and Etta May Cox Davis. There were younger children not pictured-- Elmer, Elvin, Chester and Silver. Note the windmill over Bertha's shoulder-- the Davis's were rural folks, Elmer supported his large family by farming.
On the front of this photo is written, "Three sisters 1913" and on the back--"Bertha and Cora wore these black taffeta skirts to our father's funeral. Mine was black too." I think Iva probably wrote this though I'm not sure why there are two different dates on the picture. Apparently it was taken three years after the funeral. The girl's father did die in 1910, and the ages as written are correct for that year according to the 1910 census of Lincoln Township.